runoff: Calculates runoff

In ilyamaclean/ecohydrotools: hydrogical modelling for ecological applications with R

Description

runoff calculates direct runoff based on USDA Run-off curve number

Usage

runoff(rain, cn, sm, Smin, Smax)

Arguments

rain	rainfall in mm
cn	run-off curve number (see details)
sm	Soil water fraction
Smin	Residual water content (cm^3 / cm^3)
Smax	Volumetric water content at saturation (cm^3 / cm^3)

Details

Applies the United States Department of Agriculture method for calculating direct runoff. Runoff curve numbers can be obtained from here: https://www.wcc.nrcs.usda.gov/ftpref/wntsc/H&H/training/runoff-curve-numbers1.pdf Adjustemnts for antecedent moisture condition are automatically applied, so the supplied value of cn should be for average soil moisture (AMC II). Smin and Smax values for soil types are given in soilparams().

Value

direct runoff in mm

Examples

rain <- c(1:150)
ro1 <- runoff(rain, cn = 50, sm = 0.4, Smin = 0.074, Smax = 0.422)
ro2 <- runoff(rain, cn = 90, sm = 0.4, Smin = 0.074, Smax = 0.422)
plot(ro1 ~ rain, type = "l")
plot(ro2 ~ rain, type = "l")

ilyamaclean/ecohydrotools documentation built on June 10, 2019, 5:45 a.m.